Cleaner technology — being used in the brick kilns, which is one of the major causes of air pollution in the Kathmandu valley — has raised hopes to reduce the emission by saving energy. "Most of the brick kilns in the valley have switched over to the new technology, as it reduces energy consumption and ensures quality production," said Ramesh Prasad Nepal, senior energy efficiency advisor at ESPS. According to him, use of cleaner technology ensures reduction in emission of harmful gases such as carbon dioxide and carbon monoxide while burning brick using coals, while in other hand, it reduces consumption of energy and saves money. "The moving bull trench kilns have been completely replaced by the fixed kilns in the valley, which has also made easy to install new technology," said Nepal, adding that the suspended particulate matter (SPM) after use of the new technology has come down to the standard level of about 950 microgram per cubic metre.

"It used to be awfully high even up to 2,000 SPM," he said. Increasing switch over to the new cleaner technology is mainly due to energy cost saving and quality production in larger quantity, says Shyam Maharjan, director of Quality Brick Factory, at Lubhu in Lalitpur. "Most of the brick factories in the valley have now fixed kilns and adopted the cleaner technology. The brick production using the new technology is costlier, as it requires big investment in the beginning. But it is good in a long run and environment friendly," Maharjan said. The main advantages in the new technology is energy cost saving and quality production at large quantity, which pays for the initial investment, he said, adding that the production of grade ‘A’ brick is now over 90 per cent, which used to be around 40 per cent in older technology.

"Besides fixed kilns, improved stacking of green bricks and complete combustion of coal and zigzag firing are some of the new ideas being used in the cleaner technology," said Sanjay Shah, head of Institute of Environment Management (IEM), which provides training for brick entrepreneurs to use the new technology. About 150 brick kilns in the valley have now switched over to the new technology. These kilns have changed their kilns into fixed draft and natural draft as well as vertical shaft brick kiln (VSBK).